chine, on which are placed two tanks, each holding a little more 

 than one-half the capacity of the spray tank. If it is not fea- 

 sible to get two tanks, four 50-gallon barrels may be used, two 

 of which will be for the lime and the other two for the copper 

 sulphate. The two tanks should be so connected that the con- 

 tents of both will flow into a common pipe and from that into 

 the spray tank. The solution from the lime barrels should flow 

 into one pipe and the solution from the copper sulphate barrels 

 into another pipe. The two pipes should then be connected with 

 a common pipe which leads to the sprayer. The purpose of this 

 connection is to have the diluted lime and diluted copper sul- 

 phate solutions flow into the sprayer as one stream. The stock 

 solutions should never be brought together before dilution be- 

 cause a chemical combination results which is dangerous to the 

 fruit and the foliage. 



If stock solutions each contain 2 pounds of material to 1 gal- 

 lon of water and it is desired to make 250 gallons of spray, 7% 

 gallons of the copper sulphate stock may be placed in one of the 

 tanks and diluted to 125 gallons; and 10 gallons of the lime 

 stock, after stirring well, may be placed in the other tank and 

 diluted to the same amount. These two solutions should be 

 well stirred and then the valves opened so that the two streams 

 will flow into the spray tank at the same time. This material 

 should be strained through a 20 to 40 mesh strainer. Poison 

 may now be added and the material is ready to be applied to 

 the tree. 



The spray to be used depends upon the nature of the insect 

 or plant disease to be controlled and upon the weather condi- 

 tions which prevail at the time of spraying. If the insect has 

 sucking mouth parts, such as plant lice and San Jose scale, a 

 "contact spray" must be used, but if the insect has biting 

 mouth parts, such as the codling moth and curculio, an arseni- 

 cal spray should be used. The contact sprays most commonly 

 used are the lime-sulphur solution, the miscible oils, kerosene 

 emulsion, whale-oil soap, and some of the nicotine Sprays, while 

 the stomach poisons commonly used are arsenate of lead and 

 paris green. While paris green has the higher percent of 

 arsenic and consequently the greater killing powers, it is not 

 as safe to use on fruit trees as arsenate of lead and does not 

 adhere to the leaves as well. 



